Internal-combustion engine.



A. ROSNER.

INTERNAL coIvIBusTIoN ENGINE.

APPLICATION FILED MAY I. I9II.

Patented Feb. 13,1917

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A. ROSNER. INTERNAL COMBUSTION ENGINE.

APPLICATION FILED MAY I. I9II.

Patented Feb. 13, 1917.

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INTERNAL COMBUSTION ENGINE.

APPLICATION FILED MAY l. 19H. L21 5,869. Patend Feb.-13,1917.

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INTERNAL COMBUSTION ENGINE.

APPLICATION FILED MAY l |911.

Patented Feb. 13, 1917.

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A. ROSNER.

INTERNAL COMBUSTION ENGINE.

APPLICATION HLED MAYI. 1911.

Patented Feb. 13, 1917.

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Patented Feb. 13, 1917.

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A. ROSNER.

INTERNAL COIVIBUSTION ENGINE.

APPLICATION FILED MAY l. 191|.

Patented Feb. 13, 1917.

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ADoLrH no sivnra, or BiaIDeEronr, coiynnoriou'r, AssIGNon To THELoCoMoBILn COMPANY oF AMERICA, or NEW YORK, 1v. Y., 'A CORPORATION-0FWasi: VIRGINIA.

INTERNAL-COMBUSTION fEfvGINE' To all whom t may concern.'

Be it known that I, ADoLPH RosNER, a subject of the Emperor ofAustria-Hungary, and a resident of Bridgeport, 'county of Fairfield,State of Connecticut, (whose postoflice address is 1166 Kossuth street,Bridgeport, Connecticut), have invented an Improvement'inInternal-Combustion Engines, of which the following description, inconnection with the accompanying drawings, is a specification, likecharacters on the drawings representing-like parts'.

This inventionrelates to internal combustion engines and particularly tothe means for controlling the admission offuel to the cylinder and theexhaust 'of the waste gases therefrom.

In carrying out my invention I preferably make .use of slide valves.rThe valves as herein disclosed, however, are so designed and disposedthat an extremely high degree of compression can be readily attainedvwhile, at the same time, the valvesare simple'in construction andoperation and are free from the difficulties of lubrication, overheatingand other troubles to which valves of this class have heretofore beensubjected.

The invention will be best understood by 4reference to the followingdescription when taken in connection withthe accompanying villustrationof one specific embodiment thereof, while its scope will be moreparticularly pointed out in the appended claims,

In the drawings: v j i Figure 1 is a transverse sectional elevationvtaken through one cylinder of a double-cylinder engine equipped withone form of my I invention;

Fig. 2 is a plan partly in section taken onJ the line 2-2 in' Fig. 1;

Fig. 3 is a section in plan partly broken away taken on, the line 3-3 inFig. 1; 7

Fig. 4 is a perspective view showing the pair of arc-shaped slide valveplates;

, Fig. 5 is a plan view showing the supple.-v

mental spring ring for assisting in. seating the valves; l,

Fig. 6 is a side elevation of the engine partly in section taken on aplane at right angles toftlieV plane of the section shown in and theexhaust ports with -a common exhaust space 16 and exhaust Pipe (not Fig.1;

Fig. 7 is a'sectional elevation similar to Fig. 1 showing a modifiedconstruction;

Figs. 8, 9, 10,11, 12 and'13 show further modifications; j

A'l5-15 in Fig. 13;

v otherwise located,

Specification of Letters Patent.A

PatentedllFeb. 113, 1911"?.

Application mea May 1, 1911.' serial 110.624,32'4.

Fig.`14 is a plan view' of the engine shown in Fig. 13 partly brokenaway;

plan on .the line Fig. 15 is a section in Fig. 16 shows in'sectionalelevation a further modification;

"Fig 17 is a section in plan on the line 17- 17 in Fig. 16; and i Figs.18, 19, 20 and 21 are sectional elevations partly diagrammatic showingthe pist0n and valves in different positions.

Referring to the drawings ,and particularly to the embodiment of theinvention shown in Fig. 1 the engine thereillustrated is provided with afixed main cylinder 1, supported upon the crank casing 2. A. workingpiston 3 is provided being connected by. i the connectingrod 4 to thecrank 5 and crank shaft 6. The working space of the cylinder, or thatthrough which the piston-travels, is surrounded by the water jacket 7and the piston slides in direct contact with the water jacketed walls ofthe fixed cylinder. ,The

rear end of the cylinder is closed by the cyl- 80 inder head 8 which isbolted or otherwise fixedly secured to the top or end of the cylinderforming'a gas tight joint and a gas tight closure for the end of thecylinder.` The cylinder head has the portion 9 which projects into therear end of the cylinder, the projecting portion being of lesserdiameter than the diameter of the cylinder providing thereat an annularspace 10 between the cylinder and .the-rentrantv walls of the head. The

" cylinder head has the centrally arranged spark plug 11 and is providedalso with the water jacket 12. v

At the rear of the cylinder, beyond the working space thereof, and inclose approxi- .mation to the projecting portion -of thencylinder lheadare provided the oppositely disposed admission Vand exhaust ports 13 and1 4, respectively. While these ports might be they are preferablyformedA directly in the walls of the cylinder bore itself and as shownin Figi7 3 extend each Apartwa'y `around'the cylinder, the ad' imissionports of each pair of cylinders coinmunic. ting "with a commonadmission space 15 and supply pipe (the latter not shown) shown).

In the described embodiment of the invention the ports 14' and 15 arecontrolled. by

independently movable slide valves 17 and 18, respectively. While thevalves might consist of flat plates or have other than a curvilinearshape, for convenience in construction as Well as more eicientoperation, each valve preferably comprises an arcshaped butnon-cylindrical segmental plate having a curvature corresponding to thecurvature of the cylinder bore so that it is adapted to seatthereagainst. j

These valve plates or slides are moved independently up and down bymeans to be fully described so that their ends which in their lowermostpositions terminate short of the piston and the Working space of thecylinder, are alternately projected each over its respective port toclose the sameA and Withdrawn therefrom to open the port. The valvesides at their inner faces are exposed to the pressure of the gascontained in the cylinder so that they are automatically seated duringthe compression and Working strokes of the piston, the high pressureexerted radially outward against the valves, holding them effectivelyeach against its seat, preventing all leakage at the ports.A

' The inner faces of the slides are not required to fit closely or seatagainst the projecting Walls of the cylinder head. On the contrary,there is preferably provided (as shown in Fig. 1) a slight clearancebetween the cylinder head and the slides so as to permit free access opressure from the cylinder space to the back or inner sides of thevalves above the explosion space of the engine. The \valves beingautomatically 'seated by. the pressure Within the cylinder space, thefree access of pressure to the annular space at the back of the valvesis preferable rather than harmful and the valves asshovvn may be lessthan semi-cylindrical with their longitudinal edges out of contact andseparated by a space of any desired Width so long as sufficient lap isprovided to cover the ports.

To move the valves independently and in properly timed relation,actuating devices arelprovided having connection with the valves throughopenings 19 and 20 formed in the cylinder Walls and in the seat overWhich the valves slide. In the openings 19 and 20 there are pivoted theactuating levers 21 and 22, respectively, Which are connected to thevalves at their outer sides orpfaces by means of the trunnions 23 and24, respectively seated in the depressions or pockets 25 and '26(seeFig. 4) formed in thevalves.

The openings 19 and 2O being formed in the cylinder and the valves beingpressed automatically thereagainst by the pressure Within the cylinderspace, all leakag'e is prevented through the openings in the same.manner as it is through the ports 13 and 14 when the latter are closed.

""@To actuate the valves the levers 21 and 22 are jointed respectivelyto the push rods 27 and 28, the latter being connected at their lowerends with the cam rolls 29 and 30 engaging respectively the actuatingcams 31 and 32 on the cam shafts '33 and 34. These cam shafts aredriventhrough gears 35 and 36, meshing with the pinion 37 on the crankshaft at one-half the speed of the crank shaft. Each cam isprovided-With one depression Which, when brought beneath the cam roll,permits its respective valve to move back into the annular space andopen its respective `port under the pressure of a valve opening spring,such opening movement, therefore, taking place once for each two doublestrokes of the piston.

It Will be observed that the cam is effective'for positively closing andmaintaining' the valve closed during compression and ring, While springpressure is utilized for opening the valve at the appropriate time. lThe springs herein are provided at 38 and 39 which hold the cam rolls ofthe respective push rods against the edges of the cams 31 and 32. Thepush rods and associated parts are housed in by the protecting casings40 and 41. j

Inasmuch as the admission valve is not opened until after the piston isstarted on its admission stroke and there is momentarily a slightsuction created, there is preferably provided supplemental means forholding each valve, and particularly the eX- haust valve, against itsseat in spite of such suction, as Well as to resist tendencies at anyother time for the said valves to lift from their seats. Suchsupplemental means here- 1n comprises a spring ring 42`(see Figs. 1

and 5) seated in a recess in the projecting Y Referring to Figs. 18 to21, inclusive, the operation of the valves will be readily apparent. InFig. 18 the piston is shown during its admission or suction stroke, thead mission valve 17having. been retracted into the annular 'space andhaving opened the s admission port 13 to they cylinder. The exhaustvalve 18 has been previously closed and is still maintained closed byits cam 32. The conditions which pertain during the compression strokeare represented in Fig. 19. The "piston is there shown as having startedbn the compression stroke, the admission valve 17 having been previouslyclosed by its cam 31 and the exhaust' valve -being still maintainedclosed by its cam 32.

. Under these conditions the increasing comiso :terasse presses thevalves against their respective seats so that as the compressionincreases, 'so also does the resistance to leakage at and about thevalves.

In Fig. 20, the conditions at the commencement of the working stroke arerepresented, the iston having'started on its second forwar movement andboth the valves being still maintained closed by their respective cams.

In Fig. 21 the piston is shownas having completed its working stroke andas starting on the return or exhaust stroke, the exhaust valve 1,8having been permitted to open by its cam at the commencement ofthestroke.

The valves may be given a very short stroke, herein the equivalent onlyof the port opening plus the necessary lap, and through the use of thecams as actuating agents may be moved each at such an appropriate timeas gives the most effectively timed lport opening for admission andexhaust. Thus, during suction stroke, the admission. valve can be openedalmost instantly after the commencement of the admission stroke andremain open until a little after the completion of the stroke. On 'theother hand, the exhaust` valve may be opened near the very close of theworking stroke and can be kept open until the comletion of the exhauststroke of the piston.

y modifying the shape ofthe cams the precise timing of the valves can beindepently varied as may be desired and preferably I so set the camsthat the exhaust valve is not closed until a few degrees after thecompletion of the exhaust stroke of the pisj minimum of wear.

moreover that the valves are only 1n motion ton and not until theadmission valve has started to open, so that there is a slight intervalduring which both valves are opened. permitting a momentary scavengingaction.

lThe opening and closing movements of the-valvesin each case areeffected 'very rapidly by means of the cams. This adds materially to theeffectiveness of the admission, compression, working, and `exhauststrokes. 1

The cam-operated movement of the valves and the short travel requiredproduces a It will be observed y when the internal pressure is slight,periods of compression and firing occurring when the valves arestationary. This not only reduces the frictional wear of the valves butalso the'power required to move them and providesconditions which assistin preventing leakage.

The valves as herein shown are preferably located at. the'v rear of theworking space of the cylinder and out of contact with the piston, thisplacingthem out ofthe direct path of heat conduction or dispersion*which takesplace from the working cylinder space ,through the cylinderwalls to the water jacket. Thel slide valves therefore are not onlythemselves out of the direct path of heat which must Ivbe dissipatedthrough the cylinder walls and that intense Iheat which tends tointerfere with ytheir elkective operation is avoided, but the cooling ofthe cylinder is much more eectively carried out where the heat does nothave to traverse the valves themselves interposed between the piston andthe cylinder walls. I,

While the access of pressure fluid to the annular space 10 is. permittedto hold the valves seated, their location with the major portion of eachwithin the annular space between the cylinder head and the cylinder,

causes them to be shielded to a large extent by the projecting cylinderwalls from the intense heat of the combustion chamber during the workingstroke, the only portion of the valves which are exposed to the intenseheat of combustion being the short projecting ends which cover theports.

`While the valves might be arranged upon seats not constituting a partof the cylinder bore, preferably, as herein shown, they are seated in acontinuation of the cylinder bore, being, however, ima non-concentric ornonoverlapping relation to the piston. Furthermore, while it is notessential for the operation of the valves that the cylinder head havethe projecting portion 9, by lemploying such portion it permits theintroduction of the water jacket into the end of the cylinder and theinterposition of a heat shield between the major portions' of the valvesand the explosion chamber.

In Fig. 7 there is shown ya modified form of the engine illustrated inFig. l, the push rod 44 being connected to the lvalve actuating lever 45at a point intermediate the lever fulcrum and the valve so that the ca mherein acts positively to open the valve, thespring 46 being relied uponto close the same.J I In Fig. 8 there is shown a construction -similarlto that Lshown in Fig. 1, there being employed, however, an additionalspring 4 roo at the top kof the cylinder head. pThis spring is seated ina pocket formed in the cylinder head and inclosed by the cap 48, thespring tending to lift the rod 49, the lower end 4,of which passesthrough the cylinder head and is threaded into the valve 50. This tendsto assist the main spring 38 (Fig. l) in holding the cam roll againstthe cam and eliminates all lost motion in the cams and joints betweenthe spring 38 andthe cam. Tn this construction the cam positively closesthe valve while the springs 3S and 47 open the same under elastic pres\Sure.

In Fig. 9 there is shown a spring 51 similarly located but intended toassist a main spring such as the spring 46 shown in Fig. 7 which isemployed for closing the valve. In this construction the spring tends topress downward upon the push rod 52 engaging' the valve, and, inconjunction with the spring 46, to depress the same vinto its closedposition, the cam being positively relied upon to open the valve.

In Fig. 10 the valve 17 and the valve actuating lever 21 are shownarranged the same as in Fig. 1, but a. cam shaft 53 is employed locatedat the side of the cylinder and near the top thereof, so that the cam 54acts directly upon the cam roll 55 carried by the actuating lever 21itself. This avoids the necessity of the push rods, the valve beingopened herein by a 'spring 56 contained within the cap 57 and pressingdownwardly upon the flanged sleeve 58 operatively connected to the lever21.

In Fig. 11 a similar construction is shown, the opening spring 59,however, being seated in a pocket of the cylinder head inclosed by thecap 60 and tending to lift the rod 61, the lower end of which projectsthrough the cylinder head and is secured to the valve.

In Fig. 12 an arrangement similar to that in Fig. 11 is shown, thespring 62, however, being relied upon to close the valve by pressingdown upon the valve pusher rod 63, the cam 64 and cam shaft 65 hereinbeing located above the cam roll so that the cam serves positively toopen the valve.

In Fig. 13 a further modification is shown wherein the two cylinders areoperated from a single cam shaft 66 placed above the'cylinder head. Thetwo slides are operated by connections similarly but reversely arranged.Taking for example the admission slide 67, this has secured to the outerside thereof the actuatingrod 68, the upper end of lwhichis pivoted tothe lever 69. TheI latter has its rear end pivoted tothe link 70 andcarries the cam roll 71 engaging the cam 72. The spring 73 seated in thecylinder head is operatively `connected to the lever 69 at 74 tending tolift the lever to hold the cam roll to the cam and open the valve whenthe cam permits. In the form shown in Fig. 13, the slides have twobearing seats, one in the cylinder bore and one in the larger diameterbeyond the cylinder bore.

In Fig. 16 there is shown a modification wherein the bearing seat forthe slides are the same diameter throughout as the cylinder bore. theslide 76 is secured to the same between the rentrant walls of the headand the portion of the cylinder against which the valve seats, the rodpassing through the head and Herein the actuating rod forv connected tothe actuating lever 77. The spring 7 8 tending to lift the lever andOpen the valve isthen located in a pocket formed in the cylinder outsideof the actuating rod. Obviously the method of actuating the slide shownin Figs. 13 and l6.can be utilized while employing the springs to closethe valves instead of openingthe same.

It will be understood that the terms front, rear, top and bottom asapplied' to the engine and its cylinder are merely terms of descriptionapplied to' the specific drawings herein annexed to facilitate a moreready understandingof them, and have no significance as applied to thegeneric principles of my invention, various embodiments of which may bemade wherein the relation ofthe parts thus referred to made in theillustrated embodiment of the invention without departing from thespirit thereof.

Claims:

1. In an internal combustion engine the combination with a fixedcylinder having aoppositely dis-- bore of uniform diameter, posedadmission and exhaust ports at the rear of the working space, a piston,and a pair of independently movable and opposite ly disposednon-cylindrical arc-shaped slide valves seated against the interiorcylinder walls beyond the rearward limit of piston travel and means forindependently moving said valves for opening and clos-l ing said ports.'

2. In an internal combustion engine, the combination with a cylinder, ofapiston, said cylinder having admission and exhaust ports in theexplosion chamber, independent slide valve plates arranged to open andclose said ports and located beyond the rearward limit of piston travel,said valve plates being exposed to'the pressure of the working cylinderspace and means for independently moving said valve plates.y

3. In an internal combustion engine, the

combinationwith a cylinder, of" a piston, said cylinder having admissionand exhaust ports at the rearof the cylinder chamber, independentarc-shaped segmental -valve plates arranged to open and closeA saidports and located beyond the rearwardlimit of piston travel, said valveplates being exposed to the pressure of the working cylinder space, andmeans moving said valve plates.

4. In an internal combustion engine, the

for independently Laisse@ l combination withl a cylinder, a piston,'saidcylinder having a port, a slide valve plate seated upon the wall of saidcylinder and controlling said port, said valve being automaticallyseated by the pressure of the gas contained within the cylinder space,and means for moving said valve plate, said wall having an openingcovered by the valve and separate from the port, through' which openingthe valve moving `means passes.

5. An internal combustion engine comprising a cylinder having a waterjacketed worklng space, a Water jacketed cylinder head, said cylinderhaving admission and exhaust ports and independently movable arc-shapedvalve plates automatically seated by exposure to the pressure of the gaswith- ,in the cylinder, said plates working between 2o the walls of thecylinder and the cylinder head and out of the direct path of heatdispersion fgpm the working space to the water jacket.

6. An internal combustion engine vcom- 2'5 prising a fixed cylinder, apiston in direct contact with the walls thereof, a cylinder head forminga gas tight closure for the j rear end of the cylinder, said cylinderhaving ports and means for controlling said ports comprising a pair of`arc-shaped slide valves automatically seated under the pressure of thegas contained in the cylinder chamber and means for independently movingsaid valves comprising actuating means connecting the exterior of eachvalve and Myerking through an opening in the wall on which the valveseats.

7. In an internal combustion engine, the combination with a cylinder ofa cylinder 40 head having a portion projecting into the cylinder toleave an annular space between the same and the 'walls of theVcylinder,\a piston, said cylinder having a" port and an arc-shapedslide valve working in the said annular space and having its majorportion contained therein and adapted to be alternately projectedtherefrom and retracted to control said port.

8. In an internal combustion engine the combination with a cylinder, acylinder head forming a gas tight closure for the end of said cylinderbut having a portion projecting within the same to provide an annularspace, said cylinder being provided with ports, a pair of arc-shapedslide valves working in said annular space and out of contact with thepiston and atthe rear thereof to control said ports, and means forindependently moving said valves.

9. In an internal combustion engine, the combination with a cylinder, acylinder head having a portion projecting into the cylinder to providean annular space, a-pair of independent arcshaped slide valves working msaid 4annular space, said valves being exposed on their inner sides tothe pressure of the gas contained in the cylinder and therebyautomatically seated, said valves being outside the direct path of heatdispersion from the working space of the cylinder to the cylinder walls.

10. In an internal combustion engine, the combination with a cylinder ofa cylinder head having a portion projecting into the cylinder leaving anannular space between the same and the cylinder walls, said cylinderbeing provided with ports, ka pair of independently movable arc-shapedslide valves working in said space adapted to control said ports, saidvalves being exposed to the pressure of the gas contained in thecylinder but shielded as to their maf jor portions by the saidprojecting portion of the cylinder head from the intense heat of thecombustion chamber, and means for moving said valves.

11. In an internal combustion engine, the

Vcombination with a cylinder having a firing space, the containing.walls of said firing space being provided with a port, a slide valveplate seated on the interior of said containing walls to control saidport, Said valve being exposed to the pressure of the explosion spaceand thereby automatically seated., the portion of said wall upon whichsaid valve is seated having an opening therein separate from the portand an actuating connection for moving said valve in said opening.

12. In an internal combustion engine, the combination with a fixedcylinder having oppositely disposed admission and exhaust ports at therear of the working space, the working space of the cylinder beingsuurrounded by a water jacket, a piston working in direct contact withthe Water jacketed walls of said cylinder, a cylinder head rigidlyclamped to the fixed cylinder to form a gas tight joint therewithp buthaving a water-jacketed portion projecting into the rear portion ofthecylinder chamber providing an annular space thereat, a. pair ofindependently movable and oppositely disposed arc-shaped slide valvesseated against the interior cylinder walls and working in the saidannular space, and means for moving said valves independently. N.,

13. In an internal combustion engine, the combination with a fixedcylinder having oppositely disposed admission and exhaust ports at therear of the working space, a piston working in direct contact with thewalls of said cylinder, a cylinder head rigidly clamped to the fixedcylinder to form a gas tight joint therewith but having a portionprojecting into the cylinder chamber and providing an annular 'spacethereat, and oppositely disposed slide valves seated against the innerwalls of the cylinder space Iby the pressure of the gas containedtherein andworking in the said annular space, and means forindependently moving combination with a xed cylinder having a port atthe rear of the working space, the

"a working space of the cylinder being surrounded by a water jacket, apiston Working in direct contact with the water ja ck.v

eted walls of said cylinder, an arc-shaped slide valve seated againstthe interior cylinder walls and adapted to control said port, said valvebeing out of 'the direct path of heat dispersion from the-workingcylinder space to the water jacket and means for moving said valve tocontrol said port.

15. In an internal combustion engine, the combination with a ixedcylinder having admission and exhaust ports at the rear of the workingspace, the working space of the cylinder being surrounded by a waterjacket, a piston working in direct contact with the water jacketedcylinder, a cylinder head rigidly clamped to the cylinder to form a gastight joint therewith, independently movable arc-shaped slide valvesseated against the interior cylinder walls and having their inner facesexposed to the working,

pressure of the engine and thereby maintained tight each against itsseat during the compression and working stroke of the piston, saidvalves being outside of the direct path of heat dispersion from theworking.

space of the cylinder to the water jacket.

16. In an internal combustion engine, the combination with a ixedcylinder having oppositely disposed admission and exhaust ports at therear of the working space, the

working space of the cylinder being sur,-4 rounded by a Water jacket, apiston working in direct contact with the water jacketed walls of saidcylinder, a cylinder head rigidly clamped to the lixed cylinder to forma gas tight joint therewith but having a waterjacketed portionprojecting into the lrear end of the cylinder chamber providing anannular space between the walls of the head and the walls of thecylinder, said head projecting into said cylinder into closeapproximation to said ports, a pair-of independently movable andvoppositely disposed arcshaped slide valves seated against the interlorcylinder walls and working in the annular space, said valves being atthe rea-r of the l1m1ts of piston travel and outside of the d irect pathof heat dispersion from the working space through the cylinder walls,means for movmg said' valves independently to alternately project eachone over its respective port and Withdraw it into said annular spacethereby to provide for the admlsslon, compression, working and exhauststrokes of the piston, said moving means includmg for each valve apivoted lever, the mner ,aces of said slides being exposed to v tivelyclosing the. valve,

the working pressure of the engine and thereby maintained tight eachagainst its seat .during the compression and working stroke of thepiston. i

A 17. In an internal combustion engine, the combinationwith a fixed`cylinder having oppositely disposed admission and exhaustports attherear of the working space, the

working space of the cylinder being sur-A rounded by a water jacket, apiston working in direct contact with the water-jacketed walls of saidcylinder, a cylinder head rigidly clamped vto the fixed cylinder to forma gas tight joint therewith but having a water-ja-cketed portionprojecting into the rear portion of the cylinder chamber providing anannular space between the walls of the head andthe walls of thecylinder, said head projecting into said cylinder into closeapproximation to said ports, a pair of independently movable andoppositely dis-l posed arc-,shaped slide valves seated against theinterior cylinder walls and working in the said annular space,saidvalves being at the rear of the limits of piston travel and outsideofthe direct path Vof heat dispersion from the working space through thecylinder walls, means for moving said valves independently toalternately project each one over its respective port and withdraw it.into said annular space thereby to provide for the admission,compression, working and exhaust strokes ofthe piston, said Y movingmeans including for each valve a pivoted lever, an actuating cam forposia spring for opening the same and connections between said parts andsaid valve at the outer sideof the latter, the inner faces of saidslides being exposed to-the working pressure of the engine and therebymaintained4 tight ,each against its seat during the compression andworking stroke .of the' piston and -supplementary means forl holdingeach valve against its seat comprising 'a Vspring ring interposedbetween the inner vside of the slide andl the bead.

18. An internal combustion engine comprising a cylinder havingoppositely disposed admission and exhaust ports near the rear of theworking space, a pair of independently movable but oppositely disposedy,arc-shaped slide valves seated against the walls of the cylinder,oppositely disposed projecting Walls ofthe cylinder admission andexhaust ports in the cylinder walls between the' head and the workingspace of the cylinder, a pair of independently movable but oppositelydisposed arc- Shaped slide valves 'seated against the interior cylinderwalls between said annular space and behind the working space of thecylinder, said valves being automatically seated by exposure tocylinderpressure and means to move said valves to control said admissionand exhaust ports.

20. In an internal combustion engine, the combination with a fixedlcylinder having oppositely disposed admission and exhaust ports at therear of the working space, a piston working in direct contact withthewalls of said cylinder, a cylinder head having a portion projecting intothe cylinder chamber and providing an annular space thereatcommunicating with said working space, oppositely disposed arc-shapedslide valves seated against the inner walls of the cylinder space by thepressure containedl therein and working in said annular space, and meansfor independently moving said valves to project the same from saidannular space and cover the said ports.

21. An internal combustion engine having a cylinder comprisingoppositely disposed admission and exhaust ports near the rear of theworking space, a pair-of independently movable but oppositely disposedarcshaped slide valves seated against the interior cylinder'walls butbeyond the rearward limit of piston travel, said valves beingautomatically seated by exposure to cylinder pressure, and meansindependently to move said valves to control said admission and exhaustports, said means passing through and means for moving said Valvesindependently, said moving means passing through openings in thecylinder walls surrounding said annular space and said openings beingcovered by said valves.

` 23. In an internal combustion engine, the combination with a cylinderhaving oppositely disposed admission and exhaust ports near the rear ofthe working space, a` pair of independently?1 movable but oppositelydisposed arc-shaped slide valves seated against the interior cylinderwalls at the rear of the working space, said valves being automaticallyseated by exposure to the cylinder pressure, means for moving saidvalves each through an opening in the wall on which the valve seats.

`24:. In an internal combustion engine, the combination with a cylinderhaving oppositely disposed admission and exhaust ports near the rear ofthe working s ace, a' pair of independently movable b oppositelydisposed arc-shaped slide va ves seated against the interior cylinderwalls at the rear of the working space, said valves being automaticallyseated by exposure to the cylinder pressure, and means for moving said-valves each through an opening in the wall on which the valve seats,the opening for the exhaust valve moving means being separate from theexhaust port, thereby to protect the valve moving means from the heatedexhaust gases.

25. An internal combustion engine comprising a cylinder 1, a piston 3',saidv cylinder being provided with an inlet port 13 and an exhaust port14, and independently movable arc-shaped slide valves 17 and 18 forcontrolling said ports and located at the rear of the path ofreciprocation of the piston, said valves projecting into said cylinderand being maintained seated by exposure to the pressure therein, andmeans for reciprocating said valves. i A

In testimony whereof, I have signed my name to this specification, inthe presence of two subscribing witnesses.

A DOLPI-I ROSNER. Witnesses:

EVERETT S. EMERY, THOMAS B. BOOTH.

